BRL-CAD is a powerful cross-platform open source solid modeling system that
includes interactive geometry editing, high-performance ray-tracing for
rendering and geometric analysis, image and signal-processing tools, a
system performance analysis benchmark suite, libraries for robust geometric
representation, with more than 20 years of active development.

Optional dependencies : lz4, astyle, re2c, proj, gdal
BRL-CAD will use them if available, if not it will use bundled versions.
gdal is  used by BRL-CAD but it does not detect the SBo version and always
uses bundled one.

Also there are a few options (usage : OPTION=ON/OFF sh ./brlcad.SlackBuild)
* BRLCAD_ENABLE_RUNTIME_DEBUG=ON
Enables support for application and library debugging facilities.
Disabling the run-time debugging facilities can provide a significant
(10%-30%) performance boost at the expense of extensive error
checking (that in turn help prevent corruption of your data).
Default is "ON", and should only be disabled for read-only render
work where performance is critical.

! Warning ! None of the options below seems to actually complete the build
* BRLCAD_ENABLE_QT=OFF
Uses qt5 instead of TCL/Tk.
Requires that the qt5 package is installed.
Default value is OFF, BRL-CAD does not autodetect qt5 presence.

* BRLCAD_ENABLE_OSG=OFF
Uses OpenSceneGraph based optional features.
Requires that the OpenSceneGraph package is installed.
Default value is OFF, BRL-CAD does not autodetect OSG presence.

* BRLCAD_ENABLE_RTGL=OFF
Enable experimental RTGL code.
Default value is OFF, it is experimental.
